The present invention relates to a guidance device for guiding a blown film between a film blowing head and a take-off roller device and a method for adjusting the angles of attack of guidance segments of opposing lateral guidances of a guidance device.
Guidance devices for guiding of a blown film are basically known. For example they are characterized in WO 2009/000510 A2 and in WO 2009/000511 A2. Thereby, basically they are about manufacturing devices for blown films. For this purpose commonly blowing heads are in use which produce the blown film. Afterwards this blown film is lodged, by successively laying down both opposing sides of the blown film hose. In view of a cross section the cross section alters between mostly round to a leveled cross section by the take-off roller device based on the film blowing head. Known manufacturing devices for such blown films already use guidance devices. They are comprising for example plane guidances and lateral guidances. They are serving for providing a defined pass requirement for the blown film between the film blowing head and the take-off roller device. Particularly concerning the two opposing lateral guidances for lateral guidance of the blown film it is important, which angle is adjusted between these lateral guidances and the conveyance direction of the blown film. Particularly with segmented lateral guidances such an angle or the interaction of different angles relative to the conveyance direction are important in order to be able to provide a crease free folding of the blown film for the take-off roller device.
With known guidance devices a manual positioning for the variation of the angles is intended. In case electric gears are used, an electric actuation of the single portions of such lateral guidances is used to separately adjust each angle. This requires a huge expenditure of time and moreover a plurality of attacking positions to perform the angle adjustment. Moreover, it is not ensured, that all angles which were adjusted are matching. A non-matching angle situation for the lateral guidances can lead to the situation that a drapery causes to an increased waste of the blown film during the level process.